Abstract

Ionization is a fundamental process in intense laser–matter interactions and is known to cause plasma defocusing and intensity clamping. Here, we investigate theoretically the propagation dynamics of an intense laser pulse in a helium gas jet in the ionization saturation regime, and we find that the pulse undergoes self-focusing and self-compression through ionization-induced reshaping, resulting in a manyfold increase in laser intensity. This unconventional behavior is associated with the spatiotemporal frequency variation mediated by ionization and spatiotempral coupling. Our results illustrate a new regime of pulse propagation and open up an optics-less approach for raising laser intensity.

© 2020 Optical Society of America

Impact-ionization mediated self-focusing of long-wavelength infrared pulses in gases

Xiaohui Gao and Bonggu Shim
Opt. Lett. 44(4) 827-830 (2019)

Ionization-assisted spatiotemporal localization in gas-filled capillaries

Xiaohui Gao, Gauri Patwardhan, Bonggu Shim, Tenio Popmintchev, Henry C. Kapteyn, Margaret M. Murnane, and Alexander L. Gaeta
Opt. Lett. 43(13) 3112-3115 (2018)

Ionization-assisted refocusing of femtosecond Gaussian beams

Xiaohui Gao, Gauri Patwardhan, Bonggu Shim, and Alexander L. Gaeta
Opt. Lett. 44(23) 5888-5891 (2019)

Subcycle spatiotemporal compression of infrared pulses in χ⁽²⁾ semiconductors

A. Hofstrand and J. V. Moloney
Opt. Lett. 45(21) 6006-6009 (2020)

Theory of the quasi-steady-state self-focusing of partially coherent light pulses in nonlinear media

Huan Wang, Xiao-Ling Ji, Yu Deng, Xiao-Qing Li, and Hong Yu
Opt. Lett. 45(3) 710-713 (2020)